The present invention relates to apparatus and methods for making bags or packages, and, more particularly, concerns a multiple purpose convertible vertical form, fill and seal machine and method for making a variety of styles or types of bags including overlap or fin seals, pillow, potatochip, nonreclosable or reclosable, product-filled bags and especially zipperlock recloseable bags.
Package or bag making machines generally referred to as vertical form, fill and seal machines and methods for manufacturing individual pillow type packages with nonreclosable, midline overlap longitudinal seams or seals are described, for example, in U.S. Pat. No. 2,200,971 to Sonnebbrn et al., granted May 14, 1940 (U.S. Cl. 93-3); U.S. Pat. No. 2,145,941 to Maxfield, granted Feb. 7, 1939 (U.S. Cl. 93-3); U.S. Pat. No. 2,154,521 to Maxfield, granted Apr. 18, 1939 (U.S. Cl. 93-3); U.S. Pat. No. 2,852,898 to Berg, granted Sep. 23, 1958 (U.S. Cl. 53-182); U.S. Pat. No. 2,869,298 to Zwoyer, granted Jan. 20, 1959 (U.S. Cl. 53-51); U.S. Pat. No. 2,960,808 to Pike, granted Nov. 22, 1960 (U.S. Cl. 53-24); U.S. Pat. No. 3,055,154 to Markley, et al., granted Sep. 25, 1962 (U.S. Cl. 53-182); U.S. Pat. No. 3,262,244 to Cutler, et al., granted Jul. 26, 1966 (U.S. Cl. 53-182); U.S. Pat. No. 3,425,185 to Samways, et al., granted Feb. 4, 1969 (U.S. Cl. 53-182); U.S. Pat. No. 3,466,850 to Hudson, et al., granted Sep. 16, 1969 (U.S. Cl. 53-28); U.S. Pat. No. 3,530,642 to Leimert, granted Sep. 29, 1970 (U.S. Cl. 53-180); U.S. Pat. No. 3,925,139 to Simmons, granted Dec. 9, 1975 (U.S. Cl. 156/358); U.S. Pat. No. 4,023,327 to Simmons, granted May 17, 1977 (U.S. Cl. 53/51); U.S. Pat. No. 4,040,237 to O""Brien, granted Aug. 9, 1977 (U.S. Cl. 53/180); U.S. Pat. No. 4,043,098 to Putnam, Jr., et al., granted Aug. 23, 1977 (U.S. Cl. 53/180); U.S. Pat. No. 4,077,308 to Scully, granted Mar. 7, 1978 (U.S. Cl. 93/19); U.S. Pat. No. 4,117,647 to Rossi, granted Oct. 3, 1978 (U.S. Cl. 53/502); U.S. Pat. No. 4,128,985 to Simmons, granted Dec. 12, 1978 (U.S. Cl. 53/51); U.S. Pat. No. 4,136,505 to Putnam, Jr., et al., granted Jan. 30, 1979 (U.S. Cl. 53/551); U.S. Pat. No. 4,171,605 to Putnam, Jr., et al., granted Oct. 23, 1979 (U.S. Cl. 53/552); U.S. Pat. No. 4,144,693 to Ogata, granted Mar. 20, 1979 (U.S. Cl. 53/433); U.S. Pat. No. 4,288,965 to James, granted Sep. 15, 1981 (U.S. Cl. 53/451); U.S. Pat. No. 4,501,109 to Monsees, granted Feb. 26, 1985 (U.S. Cl. 53/451); U.S. Pat. No. 4,532,753 to Kovacs, granted Aug. 6, 1985 (U.S. Cl. 53/451); U.S. Pat. No. 4,768,327 to Mosher, granted Sep. 6, 1988 (U.S. Cl. 53/451); U.S. Pat. No. 4,965,986 to Klinkel, granted Oct. 30, 1990 (U.S. Cl. 53/551); U.S. Pat. No. 4,999,974 to Kovacs, et al., granted Mar. 19, 1991 (U.S. Cl. 53/434); and U.S. Pat. No. 5,279,098 to Fukuda, granted Jan. 18, 1994 (U.S. Cl. 53/451). Typically, a heat sealable web material is supplied from a roll and is guided to a former located at the upper end of the machine. The former folds the flat web material into a vertically oriented tube surrounding a tubular filling mandrel or pipe. The edges of the folded web material overlap one another, and, as the folded tube moves downwardly over the mandrel, the overlapped marginal edge portions are heat sealed to one another by a cyclicly operated longitudinal sealing mechanism. The web is thus formed into a web tube which is advanced through the machine in package length increments. As packages are formed by the machine, product is also filled into them by a feeder device located on top of the machine. The feeder device is driven in synchronism with the remainder of the machine and cyclicly discharges measured quantities or charges of product into the upper end of the filling mandrel. A transverse or end sealing mechanism below the filling mandrel forms package end seals in the web tube by cyclicly flattening the tube and heat sealing the two layers of the flattened tube to one another through the use of two relatively moving jaws which reciprocate toward and away from the web tube from the front and back of the machine. During one closing movement of the jaws, the sealing mechanism simultaneously forms the top end seal of the leading package and the bottom end seal of the following package, and it also cuts the web material between the two seals to separate the leading package from the web tube. Between successive operations of the jaws, the web tube is advanced in package length increments by vertically reciprocating the sealing jaws or by using intermittently operated feed belts.
In the above-mentioned patents, the midline longitudinal overlap or fin seam or seal is formed as the web material lays relatively flat against the product filling pipe or mandrel. Packaging machines which form longitudinal fin seams or seals while the edges of the web material extend outwardly from the product filling mandrel are described, for example, in U.S. Pat. No. 5,255,497 to Zoromski, et al., granted Oct. 26, 1993 (U.S. Cl. 53/551) and U.S. Pat. No. 4,691,499 to Umeda, et al., granted Sep. 8, 1987 (U.S. Cl. 53/451).
Vertical form, fill and seal machines and methods for making reclosable bags from a bag forming film and a separate plastic zipper element with edge fin seals which extend outwardly from the product fill pipe are described, for example, in U.S. Pat. No. U.S. Pat. No. 4,709,533 to Ausnit, granted Dec. 1, 1987 (U.S. Cl. 53/451); U.S. Pat. No. 4,894,975 to Ausnit, granted Jan. 23, 1990 (U.S. Cl. 53/412); U.S. Pat. Nos. 5,400,565 and 5,505,037 to Terminella, et al., granted Mar. 28, 1995 and Apr. 9, 1996, respectively (U.S. Cl. 53/133.4). The plastic zipper element is fed between the film edges and the film and zipper are joined by vertically oriented heated sealing bars. The thus formed and sealed tube is filled with product through the fill tube and horizontal cross-seals and cross-cutters complete the individual bags. In these machines, the vertical and horizontal seals are formed by sealing members or jaws which reciprocate toward and away from the plastic film from the right and left sides of the device.
U.S. Pat. No. 4,355,494 to Tilman, granted Oct. 26, 1982 (U.S. Cl. 53/416); U.S. Pat. No. 4,745,731 to Talbott, et al., granted May 24, 1988 (U.S. Cl. 53/451); U.S. Pat. No. 4,829,745 to Behr, et al., granted May 16, 1989 (U.S. Cl. 53/451); U.S. Pat. No. 4,869,048 to Boeckmann, granted Sep. 26, 1989 (U.S. Cl. 53/451); and U.S. Pat. No. 5,054,270 to McMahon, granted Oct. 8, 1991 (U.S. Cl. 53/552) describe vertical form, fill and seal machines which produce reclosable, edge fin seal bags or packages from a film or web having respective zipper profiles integral with or attached to each edge of the film.
Vertical form, fill and seal machines and methods for making reclosable pillow bags with a midline overlap or fin seal and a zipper element running along one side edge are described in U.S. Pat. No. 4,840,012 to Boeckmann, granted Jun. 20, 1989 (U.S. Cl. 53/410) and U.S. Pat. No. 5,127,208 to Custer, et al., granted Jul. 7, 1992 (U. S. Cl. 53/412).
Each of U.S. Pat. No. 4,617,683 to Christoff, granted Oct. 14, 1986 (U.S. Cl. 383/63) and U.S. Pat. No. 4,909,017 to McMahon, et al., granted Mar. 20, 1990 (U.S. Cl. 53/410) describe packaging machines for forming reclosable pillow type bags with midline fin seals and horizontal zipper segments.
Packaging machines and methods for manufacturing tetrahedral packages are described in, for example, U.S. Pat. No. 2,741,079 to Rausing, granted Apr. 10, 1956 (U.S. Cl. 53-180); U.S. Pat. No. 3,082,586 to Schneider, et al., granted Mar. 26, 1963 (U.S. Cl. 53-182); U.S. Pat. No. 3,090,175 to Berglund, granted May 21, 1963 (U.S. Cl. 53-28); U.S. Pat. No. 3,470,672 to Tuma, granted Oct. 7, 1969 (U.S. Cl. 53-59); and U.S. Pat. No. 3,546,835 to Mobley, granted Dec. 15, 1970 (U.S. Cl. 53-28).
Attempts have been made to provide a vertical form, fill and seal machine which produces more than one type of package. For example, packaging machines with vertically reciprocating cross-sealing jaws mounted on a 90xc2x0 rotatable platform for making nonreclosable tetrahedral or pillow type packages are described in U.S. Pat. No. 3,320,719 to Murray, granted May 23, 1967 (U.S. Cl. 53-182); U.S. Pat. No. 3,320,720 to Murray, granted May 23, 1967 (U.S. Cl. 53-182); U.S. Pat. No. 3,320,721 to Murray, granted May 23, 1967 (U.S. Cl. 53-182); and U.S. Pat. No. 3,332,206 to Murray, granted Jul. 25, 1967.
U.S. Pat. No. 4,874,257 to Inagaki, granted Oct. 17, 1989 (U.S. Cl. 383/63), describes a vertical form, fill and seal apparatus for making reclosable, edge fin seal bags or reclosable, midline fin seal pillow bags. The apparatus is shown to include two different pairs of cross-sealing jaws.
Various zippered and zipperlock packages are seen in the following patents: U.S. Pat. No. 6,059,456 entitled RECLOSABLE PROFILE ARRANGEMENT USING SLIDABLE CLOSURE STRIP, U.S. Pat. No. 5,924,173 entitled END POSTS FOR PLASTIC ZIPPER, U.S. Pat. No. 5,896,627 entitled HIGH-STRENGTH SLIDE R FOR A RECLOSABLE BAG, U.S. Pat. No. 5,833,791 entitled CONFORMING END STOPS FOR A PLASTIC ZIPPER, U.S. Pat. No. 5,775,812 entitled TAMPER-EVIDENT RECLOSABLE PLASTIC BAG WITH BREAKAWAY SLIDE R, U.S. Pat. No. 5,713,669 entitled PLASTIC BAG WITH ZIPPER SLIDE R CAPTURED IN POCKET, and U.S. Pat. No. 5,669,715 entitled TAMPER-EVIDENT RECLOSABLE PLASTIC BAG WITH SLIDE R, the teachings of which are expressly incorporated by reference herein.
Although the above-described patents provide examples of vertical, form, fill and seal apparatus and methods for forming bags or packages, there is a need for an improved packaging machine which not only forms edge fin seal, reclosable or nonreclosable, product-filled bags, but also which is convertible and adapted to produce a variety of types of seals and bags, has a compact construction, is simple to convert from one type or style of bag to another, operates at high speeds, which facilitates the production of different size bags, and/or readily accommodates the addition of different types and amounts of product.
In accordance with an exemplary embodiment of the present invention, a convertible, highly adaptable, versatile vertical form, fill and seal machine and method is provided which not only makes edge fin seal nonreclosable or reclosable bags, but also has a compact construction, is easily converted to produce other styles and types of durable, substantially air tight, product-filled bags at high speed and provides for the production of different size bags and accommodates different types and amounts of product in the bags.
In accordance with another exemplary embodiment of the present invention, a vertical form, fill and seal machine and method is provided which makes edge fin seal nonreclosable or reclosable product-filled bags. In accordance with yet another exemplary embodiment of the present invention, a vertical form, fill and seal machine and method is provided which makes midline overlap or fin seal pillow style nonreclosable or reclosable product-filled bags.
Generally, the convertible vertical form, fill and seal machine and method of the present invention produces reclosable, product-filled bags by joining a reclosable zipper strip to the edges of a plastic, bag-forming film which is wrapped around a product fill tube. The zipper strip is joined to the plastic film parallel to the longitudinal axis of the fill tube by heat sealing to form a flexible, plastic tube. Separate, product-filled bags are formed by cross-sealing, filling and severing the flexible, plastic tube downstream of the product fill tube.
More particularly, the convertible vertical form, fill and seal machine of the present invention includes one or more drive sources for intermittently driving a drive and pinch roll pair, a pair of film pull belts, and a pair of zipper strip drive rollers for pulling the plastic film and the zipper strip through the machine in bag length increments. In accordance with one embodiment of the present invention, the production of different size bags is facilitated by having the common drive source activated by a control means which receives input from a registration mark sensor which senses marks on the plastic film. In accordance with another embodiment, the production of different size bags is facilitated by changing the path length of the plastic film through the machine using an adjustable idler roller. The plastic film drive roll is driven at a slightly slower speed than the film pull belts to provide the proper film tension and accommodate stretch of the plastic film as it passes through the machine.
Further, the convertible vertical, form, fill and seal machine and method of the present invention ensures for airtight seals along the edges of each reclosable, product-filled bag by having the zipper drive rollers and a bag grabber mechanism stretch or tension the bag material and a bag squeezer assembly squeeze the air out of the product-filled tube prior to severing and cross-sealing the bag material. The bag squeezer assembly also serves to eliminate unnecessary air and to compact the product in the filled bags to thereby reduce the size of the finished bags, to decrease the risk of damage to the bags during shipping, handling, and storage by reducing, if not eliminating, air pockets, and/or reducing the quantity of air in the finished bag to lessen air or frost damage to the product in the bag.
In order to accommodate high rates of bag production, for example 30-100 bags per minute, the convertible vertical form, fill and seal machine of the present invention incorporates pressurized air cooling vents adjacent each of the vertical and horizontal heat sealing bars to cool the heat seals between the zipper strip and plastic film and the heat seals along the lower and upper edges of each bag.
In accordance with an exemplary embodiment, the convertible vertical form, fill and seal machine of the present invention produces edge fin seal, reclosable, product-filled bags by repeatedly drawing bag length increments of plastic film and zipper strip down along the fill tube, heat sealing the zipper strip to the plastic film wrapped around the fill tube to form a flexible plastic tube (bag precursor) using vertically oriented platens which are reciprocated into and out of contact with the edges of the plastic film, cooling the heat seal between the zipper strip and the plastic film using pressurized air, flattening or crushing the zipper strip at bag length increments to ensure an air tight seal is formed along the edges of the bags, stretching the plastic tube transverse to the fill tube, sealing the plastic tube transverse to the fill tube, filling the plastic tube with product, incrementing the plastic tube one bag length, stretching the plastic tube transverse to the longitudinal axis of the fill tube, squeezing the air out of the product-filled tube, forming another transverse seal in the plastic tube using reciprocating heater bars which are brought into and out of contact with the plastic tube, cooling the transverse seals using pressurized air, severing the plastic tube, and ejecting a product-filled, reclosable bag.
In accordance with yet another exemplary embodiment, the convertible vertical form, fill and seal machine of the present invention produces edge fin seal, reclosable, product-filled bags by repeatedly drawing bag length increments of plastic film and zipper strip down along the fill tube, heat sealing the zipper strip to the plastic film wrapped around the fill tube to form a flexible plastic tube (bag precursor) using vertically oriented platens which are reciprocated into and out of contact with the edges of the plastic film, cooling the heat seal between the zipper strip and the plastic film using pressurized air, stretching the plastic tube transverse to the fill tube, sealing the plastic tube transverse to the fill tube, filling the plastic tube with product, incrementing the plastic tube one bag length, stretching the plastic tube transverse to the longitudinal axis of the fill tube, squeezing the air out of the product-filled tube, forming another transverse seal in the plastic tube using reciprocating heater bars which are brought into and out of contact with the plastic tube, cooling the transverse seals using pressurized air, applying a zipperlock to the zipper of the bag precursor, severing the plastic tube, and ejecting a product-filled, reclosable bag.
In accordance with another exemplary embodiment, the convertible vertical form, fill and seal machine of the present invention produces edge fin seal nonreclosable, product-filled bags by repeatedly drawing bag length increments of plastic film and cap or tear strip down along the fill tube, heat sealing the cap strip to the plastic film wrapped around the fill tube to form a flexible plastic tube (bag precursor) using vertically oriented platens which are reciprocated into and out of contact with the edges of the plastic film, cooling the heat seal between the cap strip and the plastic film using pressurized air, stretching the flexible plastic tube transverse to the fill tube, sealing the plastic tube transverse to the fill tube, filling the plastic tube with product, incrementing the plastic tube one bag length, stretching the plastic tube transverse to the longitudinal axis of the fill tube, squeezing the air out of the product-filled tube, forming another transverse seal in the plastic tube using reciprocating heater bars which are brought into and out of contact with the plastic tube, cooling the transverse seals using pressurized air, severing the plastic tube, and ejecting a product-filled nonreclosable bag.
In accordance with still another exemplary embodiment, the convertible vertical form, fill and seal machine of the present invention produces midline overlap seal, pillow style, nonreclosable, product-filled bags by repeatedly drawing bag length increments of plastic film down along the fill tube with the edges of the film overlapping one another, heat sealing the overlapping edges of the plastic film wrapped around the fill tube to form a flexible plastic tube (bag precursor) using a vertically oriented platen which is reciprocated into and out of contact with one edge of the plastic film, cooling the heat seal between the overlapping edges of the plastic film using pressurized air, stretching the flexible plastic tube transverse to the fill tube, sealing the plastic tube transverse to the fill tube, filling the plastic tube with product, incrementing the plastic tube one bag length, stretching the plastic tube transverse to the longitudinal axis of the fill tube, forming another transverse seal in the plastic tube using reciprocating heater bars which are brought into and out of contact with the plastic tube, cooling the transverse seals using pressurized air, severing the plastic tube, and ejecting a product-filled pillow bag.
In accordance with a further exemplary embodiment, the convertible vertical form, fill and seal machine of the present invention produces midline fin seal, pillow style, nonreclosable, product-filled bags by repeatedly drawing bag length increments of plastic film down along the fill tube with the edges of the plastic film abutting one another, heat sealing the abutting edges of the plastic film together to form a flexible plastic tube (bag precursor) using one or more vertically oriented platens which are reciprocated into and out of contact with one or both of the edges of the plastic film, cooling the heat seal between the edges of the plastic film using pressurized air, stretching the flexible plastic tube transverse to the fill tube, sealing the plastic tube transverse to the fill tube, filling the plastic tube with product, incrementing the plastic tube one bag length, stretching the plastic tube transverse to the longitudinal axis of the fill tube, forming another transverse seal in the plastic tube using reciprocating heater bars which are brought into and out of contact with the plastic tube, cooling the transverse seals using pressurized air, severing the plastic tube, and ejecting a product-filled pillow bag.
In accordance with still another exemplary embodiment, the convertible vertical form, fill and seal machine of the present invention produces reclosable, product-filled pillow style bags by repeatedly drawing bag length increments of plastic film and zipper strip down along the fill tube, heat sealing the edges of the plastic film to one another and heat sealing the zipper strip to the plastic film wrapped around the fill tube to form a flexible plastic tube (bag precursor) using vertically oriented platens which are reciprocated into and out of contact with the plastic film, cooling the heat seals between the edges of the plastic film and the zipper strip and the plastic film using pressurized air, flattening or crushing the zipper strip at bag length increments to ensure an air tight seal is formed along the edges of the bags, stretching the plastic tube transverse to the fill tube, sealing the plastic tube transverse to the fill tube, filling the plastic tube with product, incrementing the plastic tube one bag length, stretching the plastic tube transverse to the longitudinal axis of the fill tube, forming another transverse seal in the plastic tube using reciprocating heater bars which are brought into and out of contact with the plastic tube, cooling the transverse seals using pressurized air, severing the plastic tube, and ejecting a product-filled, reclosable pillow style bag.
In accordance with yet another exemplary embodiment, the convertible vertical form, fill and seal machine of the present invention produces reclosable, product-filled pillow style bags by repeatedly drawing bag length increments of plastic film and zipper strip down along the fill tube, heat sealing the zipper strip to the plastic film wrapped around the fill tube to form a flexible plastic tube (bag precursor) using vertically oriented platens which are reciprocated into and out of contact with the plastic film, cooling the heat seal between the zipper strip and the plastic film using pressurized air, flattening or crushing the zipper strip at bag length increments to ensure an air tight seal is formed along the edges of the bags, stretching the plastic tube transverse to the fill tube, sealing the plastic tube transverse to the fill tube, filling the plastic tube with product, incrementing the plastic tube one bag length, stretching the plastic tube transverse to the longitudinal axis of the fill tube, squeezing the air out of the product-filled tube, forming another transverse seal in the plastic tube using reciprocating heater bars which are brought into and out of contact with the plastic tube, cooling the transverse seals using pressurized air, severing the plastic tube, and ejecting a product-filled, reclosable pillow style bag.
In accordance with one example, the convertible vertical form, fill and seal machine of the present invention may be converted from a machine for making reclosable, edge fin seal, product-filled bags to a machine for making midline overlap seal, pillow type, nonreclosable bags by changing the bag forming film stock roll in the back of the machine, adjusting the film path length and machine controls for the new bag type, size, product, etc., changing the former and fill tube, and indexing the pinch seal assembly 90xc2x0 so that the respective clamping jaws are located in front and behind the plastic tube rather than to the right and left sides thereof. In accordance with a particular example, indexing of the pinch seal assembly is facilitated by having the entire assembly mounted on a base plate which is itself mounted on a drawer mechanism which allows the pinch seal assembly to be pulled forwardly out of the machine, lifted from the drawer, indexed 90xc2x0, set back into the drawer and then pushed back into the machine.
The principle object of the present invention is the provision of a convertible vertical form, fill and seal machine and method for forming a variety of styles and types of nonreclosable and reclosable, sealed, product-filled bags.
Another object of the present invention is the provision of a packaging machine for forming reclosable, sealed, product-filled bags.
Another object of the invention is the provision of a packaging machine for forming reclosable bags with zipperlocks.
Yet another object of the present invention is the provision of an improved vertical form, fill and seal machine and method for making pillow style, sealed, product-filled bags.
Still another object of the present invention is the provision of a machine and method for forming product-filled bags which facilitate the production of bags of different size and which accommodates different types and amounts of product.
A still further object of the present invention is the provision of an improved, vertical form, fill and seal machine and method for making bags which provides for a high rate of bag production.
Still yet another object of the present invention is the provision of an improved bag making machine including bag squeezing means for selectively reducing the quantity of air retained in the finished product-filled bags.
Other objects and further scope of the applicability of the present invention will become apparent from the detailed description to follow taken in conjunction with the accompanying drawings wherein like parts are designated by like reference numerals.